purge
PERJ
/pɜːrdʒ/
To flush out trapped air, gas, sediment, or unwanted impurities from a piping system or line.
Implies an intentional forcing out of contamination or air pockets using inert gas or clean fluid under flow.
The story behind the word. From Anglo-French 'purger' and Latin 'purgare' ('to cleanse or render pure'). Pipefitters adopted the term to describe clearing stagnant or dangerous oxygen mixtures out of high-purity process lines.
Word relationships
- flush: Flushing implies washing with liquid water, whereas purging often uses pressurized inert gases like nitrogen or argon.
- bleed: Bleeding is letting off trapped air or pressure slowly via a small valve; purging involves sweeping the entire volume clear.
- contaminate: Contaminating introduces unwanted foreign matter into a pipe, the exact opposite of purging.
Commonly confused with
- flush: Flushing removes particulates using high liquid flow; purging forces out gas/oxygen using pressure or inert shield gases.
Word family
- purgation (noun): The act or process of purging.
Collocations
- purge gas
- purge valve
- nitrogen purge
- purge the system
Example sentences
- "Before welding stainless pipe, technicians purge the interior with argon gas to prevent internal oxidation." Welding prep
- "You must purge air pockets from the hydronic heating loop to restore proper water circulation across radiators." Radiator service
Memory hook
PURGE PURIFIES the pipe by driving out trapped air. Flushes out air or impurities.
When not to use
Do not use for routine continuous liquid drainage or simple gravity draining without pressure or gas flow.
Fun facts
- Natural gas utilities must purge new gas mains with pure nitrogen before gas commissioning to eliminate explosive air-gas mixtures.
Take your vocabulary further with LangBlitz
Our English vocabulary app: FSRS spaced repetition, 5,000+ curated words across 119 topic groups, CEFR A1 to C2. Explore your mastery with the beautiful Vocabulary World feature.